let myChart, trendChart;
let isAdmin = false;

$(document).ready(function() {
    // 设置默认日期范围（最近30天）
    applyQuickSelect('30days');

    // 加载统计数据
    loadStatistics();
});

// 快捷时间选择
function applyQuickSelect(value) {
    if (!value) {
        value = $('#quick-select').val();
    }

    const today = new Date();
    let dateFrom, dateTo;

    switch(value) {
        case 'today':
            dateFrom = dateTo = today;
            break;
        case 'week':
            dateFrom = new Date(today);
            dateFrom.setDate(today.getDate() - today.getDay());
            dateTo = today;
            break;
        case 'month':
            dateFrom = new Date(today.getFullYear(), today.getMonth(), 1);
            dateTo = today;
            break;
        case '30days':
            dateFrom = new Date(today);
            dateFrom.setDate(today.getDate() - 30);
            dateTo = today;
            break;
        default:
            return;
    }

    $('#date-from').val(dateFrom.toISOString().split('T')[0]);
    $('#date-to').val(dateTo.toISOString().split('T')[0]);
    $('#quick-select').val(value);
}

// 加载统计数据
function loadStatistics() {
    loadOverview();
    loadUserStatistics();
    loadLeaderboard();
}

// 加载概览数据
function loadOverview() {
    const dateFrom = $('#date-from').val();
    const dateTo = $('#date-to').val();

    $.ajax({
        url: '/api/statistics/overview',
        method: 'GET',
        data: {
            group_id: 1,
            date_from: dateFrom,
            date_to: dateTo
        },
        success: function(data) {
            isAdmin = data.is_admin;

            $('#today-count').text(data.today_completed);
            $('#month-count').text(data.month_completed);
            $('#pending-count').text(data.status_counts.pending || 0);
            $('#claimed-count').text(data.status_counts.claimed || 0);

            // 更新标题和统计数据
            if (isAdmin) {
                $('#stats-title').text('全局完成统计');
                $('#trend-title').text('全局完成趋势');
                // 管理员使用全局数据
                $('#my-total').text(data.total_completed);
                $('#my-pending').text(data.claimed_pending);
                // 渲染管理员图表
                renderMyChart(data.total_completed, data.claimed_pending);
            } else {
                $('#stats-title').text('我的完成统计');
                $('#trend-title').text('我的完成趋势');
            }

            // 渲染趋势图
            renderTrendChart(data.trend);
        },
        error: handleAjaxError
    });
}

// 加载个人统计
function loadUserStatistics() {
    const userStr = localStorage.getItem('current_user');
    if (isAdmin) {
        return;
    }
    if (!userStr) {
        console.error('用户信息不存在');
        $('#my-total').text('0');
        $('#my-pending').text('0');
        return;
    }

    let user;
    try {
        user = JSON.parse(userStr);
    } catch (e) {
        console.error('用户信息格式错误', e);
        $('#my-total').text('0');
        $('#my-pending').text('0');
        return;
    }

    if (!user || !user.id) {
        console.error('用户ID不存在');
        $('#my-total').text('0');
        $('#my-pending').text('0');
        return;
    }

    const dateFrom = $('#date-from').val();
    const dateTo = $('#date-to').val();

    $.ajax({
        url: `/api/statistics/user/${user.id}`,
        method: 'GET',
        data: {
            group_id: 1,
            date_from: dateFrom,
            date_to: dateTo
        },
        success: function(data) {
            $('#my-total').text(data.total_completed);
            $('#my-pending').text(data.claimed_pending);

            // 渲染个人图表
            renderMyChart(data.total_completed, data.claimed_pending);
                },
        error: handleAjaxError
    });
}

// 加载排行榜
function loadLeaderboard() {
    $.ajax({
        url: '/api/statistics/leaderboard',
        method: 'GET',
        data: {
            group_id: 1,
            period: 'monthly'
        },
        success: function(data) {
            renderLeaderboard(data.leaderboard);
        },
        error: handleAjaxError
    });
}

// 渲染个人图表
function renderMyChart(totalCompleted, claimedPending) {
      const ctx = document.getElementById('myChart');

      if (myChart) {
          myChart.destroy();
      }

      myChart = new Chart(ctx, {
          type: 'bar',
          data: {
              labels: ['总完成数', '待完成数'],
              datasets: [{
                  label: '任务数量',
                  data: [totalCompleted, claimedPending],
                  backgroundColor: [
                      'rgba(75, 192, 192, 0.5)',
                      'rgba(255, 159, 64, 0.5)'
                  ],
                  borderColor: [
                      'rgba(75, 192, 192, 1)',
                      'rgba(255, 159, 64, 1)'
                  ],
                  borderWidth: 1
              }]
          },
          options: {
              responsive: true,
              maintainAspectRatio: true,
              scales: {
                  y: {
                      beginAtZero: true,
                      ticks: {
                          stepSize: 1
                      }
                  }
              }
          }
      });
  }

// 渲染趋势图
function renderTrendChart(trend) {
    const ctx = document.getElementById('trendChart');

    if (trendChart) {
        trendChart.destroy();
    }

    const labels = trend.map(t => t.date);
    const data = trend.map(t => t.count);

    trendChart = new Chart(ctx, {
        type: 'line',
        data: {
            labels: labels,
            datasets: [{
                label: '完成数',
                data: data,
                fill: true,
                backgroundColor: 'rgba(75, 192, 192, 0.2)',
                borderColor: 'rgba(75, 192, 192, 1)',
                tension: 0.4
            }]
        },
        options: {
            responsive: true,
            maintainAspectRatio: true,
            scales: {
                y: {
                    beginAtZero: true,
                    ticks: {
                        stepSize: 1
                    }
                }
            }
        }
    });
}

// 渲染排行榜
function renderLeaderboard(leaderboard) {
    const tbody = $('#leaderboard');
    tbody.empty();

    if (leaderboard.length === 0) {
        tbody.append('<tr><td colspan="3" class="text-center">暂无数据</td></tr>');
        return;
    }

    const currentUser = JSON.parse(localStorage.getItem('current_user'));

    leaderboard.forEach(function(row) {
        const isCurrentUser = row.user_id === currentUser.id;
        const rowClass = isCurrentUser ? 'table-primary' : '';

        let rankBadge = '';
        if (row.rank === 1) {
            rankBadge = '<i class="bi bi-trophy-fill text-warning"></i> ';
        } else if (row.rank === 2) {
            rankBadge = '<i class="bi bi-trophy-fill text-secondary"></i> ';
        } else if (row.rank === 3) {
            rankBadge = '<i class="bi bi-trophy-fill text-danger"></i> ';
        }

        tbody.append(`
            <tr class="${rowClass}">
                <td>${rankBadge}${row.rank}</td>
                <td>${row.username}${isCurrentUser ? ' <span class="badge bg-primary">我</span>' : ''}</td>
                <td><strong>${row.completed_count}</strong></td>
            </tr>
        `);
    });
}

// 导出数据
function exportData() {
    const dateFrom = $('#date-from').val();
    const dateTo = $('#date-to').val();
    const token = localStorage.getItem('access_token');

    let url = '/api/statistics/export?group_id=1';
    if (dateFrom) url += `&date_from=${dateFrom}`;
    if (dateTo) url += `&date_to=${dateTo}`;

    // 创建隐藏的下载链接
    const link = document.createElement('a');
    link.href = url;
    link.download = `statistics_${new Date().toISOString().split('T')[0]}.csv`;

    // 添加认证头（通过fetch实现）
    fetch(url, {
        headers: {
            'Authorization': 'Bearer ' + token
        }
    })
    .then(response => response.blob())
    .then(blob => {
        const url = window.URL.createObjectURL(blob);
        const a = document.createElement('a');
        a.href = url;
        a.download = `statistics_${new Date().toISOString().split('T')[0]}.csv`;
        document.body.appendChild(a);
        a.click();
        window.URL.revokeObjectURL(url);
        document.body.removeChild(a);
        showSuccess('数据导出成功！');
    })
    .catch(error => {
        showError('导出失败：' + error.message);
    });
}